Osulf II (also known as Oswulf) was the son of Eadulf III, Earl of Bernicia, and grandson of Uthred the Bold, Earl of Northumbria. Osulf’s family ruled as Earls of Northumbria from 954 until 1016, and as Earls of Bernicia until 1041, with their capital at Bamburgh.
In 1065 Morcar succeeded Tostig as Earl of Northumbria, and he appointed Osulf to rule the portion north of the River Tyne. However, because of Morcar’s resistance to William the Conqueror in 1066, he was deposed and imprisoned. William then appointed Copsig, Tostig’s former deputy, as the new Earl.
In February 1067 Copsig came north and forced Osulf to seek shelter in the hills. Osulf began to gather an army. Because Copsig was seen as an invader and a tax-gatherer for William, he was deeply unpopular amongst the Northumbrians, and Osulf had no trouble in gathering recruits. On March 12 he surprised Copsig and his men at a banquet at Newburn-upon-Tyne. Copsig fled to a nearby church, but this was set on fire, forcing Copsig out. Osulf then cut off his head.
Osulf seemed to have seized control of the earldom of Northumbria, and was not threatened by any expeditions to remove him. However in the autumn of 1067, Osulf, carrying out his duties as earl, intercepted an outlaw and was run through by the man’s spear. He was succeeded as earl by his cousin, Gospatric, who purchased the Earldom from King William.